A few years ago, Hugo Campos was diagnosed with a heart condition. Then he received an implantable cardioverter-defibrillator, or ICD, shown here in his X-ray.

Courtesy of Hugo Campos

Each year, tens of thousands of Americans are implanted with tiny battery-controlled devices that regulate the beating of their hearts. Those devices transmit streams of medical data directly to doctors.

But some patients, like Hugo Campos of San Francisco, fear they're being kept out of the loop.

Campos has a genetic heart disease called hypertrophic cardiomyopathy, which means the muscles of his heart are too thick. It's the same disease that causes 17-year-olds to suddenly drop dead on the soccer field.

A few years ago, the disease was diagnosed, and Campos was implanted with an ICD — an implantable cardioverter-defibrillator. The device saved his life one morning when he nearly collapsed on the street.

At first he felt weak, like he was going to pass out. But as his heart went into overdrive, the device kicked in, coaxing his heart back to its normal rhythm.

Campos has had other scares since then. He lives in constant proximity to death. And that's left him with a powerful desire to know everything about his health. He wears a FitBit pedometer, sleeps with a sleep monitor, and checks his blood pressure constantly.

But unlike those devices, the ICD is a mystery to him.

That's because even though Campos' ICD can wirelessly transmit data twice a day about his heart and the ICD itself, that information goes only to his doctor. Campos has to make an appointment and ask for a printout. And that, he says, just doesn't seem fair.

"It's my body, my life, my health. Why shouldn't I have access to do as I please with this data?" Campos says.

This has become his crusade, and that of a growing movement of people who call themselves "e-patients." They want access to all kinds of medical data.

But with ICD patients there seems to be an added urgency, in part, because when the device kicks in, it isn't always as painless as it was for Campos that day.

ICDs can also defibrillate the heart with a powerful and excruciating shock. In rare cases, this has happened to some patients unnecessarily.

Campos says he just wants to know as much as he can about his ICD — how well it's working, what it's detecting in his heart.

He even wrote a song, based on an old civil rights anthem, and posted it online.

"You know, Hugo is a remarkable guy," says David Steinhaus, medical director of the Cardiac Rhythm Disease Management division at Medtronic, which makes Campos' device. "We don't get very many requests like this."

Steinhaus says, in principle, the company is fine with giving patients their data directly. The problem is how to format it so it's useful to everyone. As is, the raw data is highly technical. Would patients understand it?

"You want to do it in a way that makes sense for the patient, that they can interpret correctly, so they don't generate a lot of angst and difficulty for the physician or anyone else," Steinhaus says.

To Campos, that's not the point. "Whether I can make sense of it or not, it's another problem. I should be allowed at least to have a chance to look at this data and see if I can make sense of it," he says.

Steinhaus says Medtronic is exploring ways to get Campos his ICD data. Campos says after two years of asking, he'll believe it when he sees it.

This is MORNING EDITION from NPR News. Good morning. I'm David Greene.

Today in Your Health, using social media to connect people who have rare diseases. That in a moment. First, one man's quest to get access to his own medical data. Each year, tens of thousands of Americans are implanted with tiny battery-controlled devices that regulate the beating of their hearts. Those devices transmit streams of medical data directly to doctors. But, as Amy Standen reports, some patients fear they're being kept out of the loop.

AMY STANDEN, BYLINE: One October morning, Hugo Campos was walking to meet a friend of his in San Francisco's Mission District. Suddenly, he felt weak, like he was going to pass out. He leaned against a wall and prepared to collapse.

HUGO CAMPOS: You know, the silly things that go through our minds. I was like, where am I going to fall? This ground here is filthy.

STANDEN: Then he realized: I'm alone. No one knows where I am.

CAMPOS: My reaction was to maybe call my partner or let somebody know that I was there. But there's no time. It's just too fast. You're shutting down.

STANDEN: Campos has a genetic heart disease called hypertrophic cardiomyopathy, which means the muscles of his heart are too thick. It's the same disease that causes 17-year-olds to suddenly drop dead on the soccer field. But he's lucky. A few years ago, the disease was diagnosed and Campos was implanted with an ICD - an implantable cardioverter-defibrillator. So when his heart went into overdrive, the ICD kicked in, coaxing Campos's heart back into its normal rhythm.

CAMPOS: You feel the blood rushing back into your head. It feels great. Life feels great. It feels outstanding.

STANDEN: Campos has had other scares since then. He lives in constant proximity to death. And that has left him with a powerful desire to know everything about his health. He wears a FitBit pedometer, sleeps with a sleep monitor, and checks his blood pressure constantly.

But unlike those devices, the ICD is a mystery to him. That's because even though Campos's ICD can wirelessly transmit data twice a day about his heart and about the ICD itself, that information goes only to Campos' doctor. Campos has to make an appointment and ask for a printout.

CAMPOS: You know, it's my body and it's my life and it's my health, and why shouldn't I have access to do as I please with my data?

STANDEN: And this has become his crusade, and that of a growing movement of people who call themselves e-patients. They want access to all kinds of medical data. But with ICD patients there seems to be an added urgency, in part, because when the device kicks in, it isn't always as painless as it was for Hugo that day.

ICDs can also defibrillate the heart with a powerful and excruciating shock. In rare cases, this has happened to some patients unnecessarily. Campos says he just wants to know as much as he can about his ICD. How well it's working, what it's detecting in his heart. He even wrote a song, based on an old civil rights anthem, and posted it online.

CAMPOS: (Singing) It isn't nice to grab my data from my implantable device, then to hog it, keep it from me. That's not right. I've told you twice. It isn't nice. It isn't nice. How can it be so hard to see that I am the patient, it's my data, my heart, my ICD?

DAVID STEINHAUS: You know, Hugo is a remarkable guy. We don't get very many requests like this.

STANDEN: David Steinhaus is medical director for the Cardiac Rhythm Disease Management division at Medtronic, which makes Campos's device. Steinhaus says in principle, the company is fine with giving patients their data directly. The problem, he says, is how to format it so that it's useful to everyone. As is, the raw data is highly technical. Would patients understand it?

STEINHAUS: You want to do it in a way that makes sense for the patient, that they can interpret correctly, so that you don't generate a lot of angst and difficulty for the physicians or anyone else.

STANDEN: To Campos, that's not the point.

CAMPOS: Whether I can make sense of it or not, it's another problem. I should be allowed at least to have a chance to take a look at this data and see if I can make sense of it.

STANDEN: Steinhaus says Medtronic is exploring ways to get Campos his ICD data. Campos says after two years of asking, he'll believe it when he sees it.